| 摘要 |
<p>Compounds of formula (I) are provided wherein: R?1 and R2¿ are independently selected from hydrogen, optionally substituted alkyl and optionally substituted acyl; R3 is hydrogen or an optionally substituted group selected from alkyl, aryl and aralkyl; and X is OR6, where R6 is hydrogen or optionally substituted alkyl, or NR4R5, where R?4 and R5¿ are independently selected from hydrogen and optionally substituted alkyl, optionally substituted on the phenyl ring. The compounds have activity at receptor sites in the central nervous system.</p> |
